Apparatus for blasting by the use of electricity



J. H. BILLS APPARATUS FOR BLASTING BY THE USE OF ELECTRICITY Feb. 12 .1924.

Filed June 12. L922 M W C] "or nu Patented Feb. 12, 1924.

uNiTEo STATES PATENT HQ.

JOHN H. BILLS, DECEASED, LATE or DENVER, COLORADO; BY MoELrE 3. maps, AD-

v MINISTRATRIX, or DENVER, COLORADO.

APPARATUS FOR BLASTING- BY THE USE OF ELECTRICITY.

Application filed June 12, 1922. Serial No. 567,777.

1 '0 all whom it may concern ,Be it known that JOHN H. Bums, deceased, formerly residing at the city and county of Denver, in the State of Colorado.

did invent certain new and useful Improvements in Apparatus for Blasting by the Use of Electricity, of which the following is a specification.

This invention relates to an improved apparatus for blasting coal and other minerals by means of electrically generated steam.

It is well known and understood among 2 the miner to enter and perform any labor untiI the fumes have been removed by ventilation.

It is the object of this invention to produce a means for blasting that shall furnish 80 no flames or heat of sufficient intensity to ignite the explosive gases and coal dust,

which is often present in the mines, and

which at the same time will not generate p any noxious fumes that will prevent the 5 immediate resumption of wor I With these and other objects in view, the invention consists of a novel arrangement and combination of parts which will be hereinafter fully described and particularly 4 pointed out in the appended claims.

In the accompanying drawing I have shown what I consider to be the preferred embodiment of the invention. Although I have shown a specific embodiment of my in- 5 vention, as the law requires, it is of course understood that changes may be made within the scope of the appended claims without departing from the spirit of my invention.

so In the drawings:

Fig. 1 shows a section through a mine, and shows my improved blasting cartridge in place ready to be exploded;

Fig. 2 shows a longitudinal section of my cartridge;

Fig. 3 shows a transverse section thereof taken on line 33, Fig. 2 and proved cartridge and shows the electrical connection.

The same reference numerals will be used to designate the same or similar parts throughout the several views.

Fig. 1 represents the roof of a room 2 in a coal mine and 3 the coal seam which has been undercut as indicated at at. At or near the top of the coal seam I provide a drill hole 5 adapted to receive the explosive cartridge 6 which is connected to a source of current 7 by means of wires 8, which are provided with a switch 9. After the cartridge is put in place, the outer end of the hole is tamped as indicated by numeral 10.

My improved blasting cartridge 6 consists of an inner tubular member 11 which is surrounded by another tubular member 12 of larger diameter and concentric with tubular member 11, so that an annular space is provided between the two tubes. The ends of the tubes may be united by welding so that they form what may be considereda unitary piece. Near each of the outer tubes 12 I provide plugs 13 which may be removed so as to permit the space between the tubes to be filled with water after which the plugs are again put into lace. These plugs are preferably screwthreaded into the side of the tube, although they may also be made of rather small diameter and driven into the holes, being held in place therein by friction only. Within the inner tube 11 I place an electric heating element which consists of a core 14 of porcelain or other refractory insulating material, about which is coiled the resistance wire 15 which may be made of any suitable size and material. The wire is preferably covered with a layer of asbestos whereby it is insulated from the sides of the inner tube. By means of wires 8 an electric curlar chamber and this becomes heated to a.

high temperature. As the water is confined the pressure will, of course, become very great as the temperature increases. The strength of the outer tube 12 should be such that. the pressure within the chamber will become sufiicient to burst the same at a point slightly below the critical temperature of the water. When tube 12 bursts the water ordinary pressure.

will be converted into steam almost instantaneously, due to the fact that it is heated far above the temperature of boiling at The pressure carried by the liberation of the superheated water will act somewhat like that of the gas generated by the burning powder, but will be somewhat more gradual whereby the coal will be fractured but not shattered to the extent that it will when powder is employed.

It will be readily seen that by the use of an explosive such as I have herein described, coal mining will be made comparatively safe from the \dangers of explosions which so frequently occur as the result of the flames emitted from the explosives now in use.

Having now described my invention, what I claim as new is 1. An explosive cartridge for mining, comprising a tubular member open at both ends and surrounded by an annular chamber adapted to contain Water, an opening the water to a hightemperature, and means 5 for conducting current to said heater.

2. A toroidal-shaped cartridge whose length exceeds its diameter, said cartridge bein formed of two concentric tubular mem .ers of different diameters whose ends are autogenously welded, whereby a closed cylindrical chamber is formed, said chamber being provided with an opening for introducing aliquid thereinto, a plug in said opening, and an electric heater element within the innermost tubular member.

In testimony whereof I afiix my signature.

MOLLIE R. BILLS, Administrat'riw of John H. Bills, deceased. 

